Chronic wounds are non-healing wounds such as diabetic ulcers and pressure ulcers. Each year, 6.5 million cases occur in the U.S., costing the economy billions of dollars. Cost-effective and efficient management of chronic wounds depends on quick assessment and diagnosis of the underlying reasons for compromised healing. Ischemia is 1 of the main complications associated with chronic wounds. Thus, a quantitative method to assess and monitor tissue oxygenation and perfusion status of chronic wounds can be an indispensable tool for prevention and cost-effective management of chronic wounds. In this STTR phase I proposal, we test the ability of a newly developed near-infrared imaging method called modulated imaging as a non-contact wound perfusion and oxygenation imager. 2 main features of the modulated imaging device are (a) its capability to provide 2D topographic maps of hemoglobin concentrations and oxygen saturation, and (b) its depth-sectioning capability to provide 3D tomographic images. In this study, these features are tested on an animal wound model that simulates chronic wounds undergoing ischemia. Specific aims are to (1) implement ischemic skin flaps in rats to simulate chronic wounds with compromised tissue oxygenation and perfusion; (2) Acquire full range of multi-spectral, multi- spatial-frequency images of skin flaps before and after surgery; (3) process and optimize images for 2D/3D mapping of hemoglobin concentrations, oxygen saturation, and water content in superficial wound. The results of this work will provide essential design for building a dedicated prototype imaging oximeter system for evaluating clinical wounds in Phase II. [unreadable] [unreadable] [unreadable]